BONE CEMENT COMPOSITION AND KIT THEREOF

Abstract

The present invention provides a bone cement composition comprising a bone matrix and a bone cement matrix formed by an acrylic polymer and an acrylic monomer, wherein the ratio of the bone matrix to the bone cement matrix is in a range from about 1:2 (g/g) to about 1:1000 (g/g). The present invention further provides a bone cement composition kit comprising a bone matrix component, a powder component, and a liquid component, respectively stored in separate containers, wherein the bone matrix component includes a bone matrix, the powder component includes an acrylic polymer, and the liquid component includes an acrylic monomer. The powder component and the liquid component are mixable to produce a bone cement matrix component. A ratio of the bone matrix component to the bone cement matrix component is in a range from about 1:2 (mL/mL) to about 1:50 (mL/mL).

Claims

1. A bone cement composition, comprising a bone matrix and a bone cement matrix formed by an acrylic polymer and an acrylic monomer, wherein the ratio of the bone matrix to the bone cement matrix is in a range from about 1:2 (g/g) to about 1:1000 (g/g), and the ratio of the acrylic polymer to the acrylic monomer is in a range from about 1:10 (g/g) to about 20:1 (g/g).

2. The bone cement composition of claim 1, wherein the bone matrix is further mixed with a vehicle to produce a bone matrix component.

3. The bone cement composition of claim 2, wherein the bone matrix component is provided in the bone cement composition in the form of clay, granule, or powder.

4. The bone cement composition of claim 2, wherein the vehicle is selected from the group consisting of cellulose, cellulose derivatives, glycerol, polyethylene glycol (PEG), glycosaminoglycan, collagen, gelatin, ethylene glycol, propylene glycol, polyhydroxyalkanoate (PHA), polylactic acid (PLA), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) (PLGA), polycaprolactone (PCL), and a mixture thereof.

5. The bone cement composition of claim 4, wherein the cellulose derivatives is selected from the group consisting of methyl cellulose, sodium carboxymethyl cellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), ethyl cellulose, hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC), and a mixture thereof; the polyethylene glycol is selected from the group consisting of polyethylene glycol 600 (PEG600), polyethylene glycol 4000 (PEG4000) and a mixture thereof; and the glycosaminoglycan is selected from the group consisting of hyaluronan, chondroitin sulfate and derivatives thereof, and a mixture thereof.

6. The bone cement composition of claim 1, further comprising a polymerization initiator, a polymerization promoter, or a polymerization inhibitor.

7. The bone cement composition of claim 6, wherein the polymerization initiator is selected from the group consisting of benzoyl peroxide, tert-butyl hydroperoxide, lauroyl peroxide, azobisisobutyronitrile, and a mixture thereof.

8. The bone cement composition of claim 6, wherein the polymerization promoter is selected from the group consisting of N,N-dimethyl-p-toluidine, 2,4,6-tris(dimethylaminomethyl)phenol, and a mixture thereof.

9. The bone cement composition of claim 1, wherein the bone matrix has a main constituent selected from phosphates, sulfates, bioglass (Na.sub.2OCaOSiO.sub.2P.sub.2O.sub.5), and a mixture thereof.

10. The bone cement composition of claim 9, wherein the main constituent is a phosphate selected from the group consisting of hydroxyapatite (HA), -tricalcium phosphate (-TCP), tetracalcium phosphate, calcium hydrogen phosphate (CaHPO.sub.4), octacalcium phosphate (Ca.sub.8H.sub.2(PO.sub.4).sub.6.Math.5 H.sub.2O), calcium pyrophosphate (Ca.sub.2P.sub.2O.sub.7), amorphous calcium phosphate (ACP), magnesium dihydrogen phosphate, magnesium hydrogen phosphate, magnesium phosphate, magnesium ammonium phosphate, magnesium ammonium phosphate hexahydrate, strontium phosphate, strontium hydrogen phosphate, strontium dihydrogen phosphate, and a mixture thereof.

11. The bone cement composition of claim 9, wherein the main constituent is a sulfate selected from the group consisting of calcium sulfate dihydrate, calcium sulfate hemihydrate, calcium sulfate anhydrate, magnesium sulfate, magnesium sulfate monohydrate, magnesium sulfate heptahydrate, strontium sulfate, and a mixture thereof.

12. The bone cement composition of claim 1, wherein the acrylic polymer is selected from the group consisting of (A) poly(alkyl acrylates) formed from the polymerization of alkyl acrylate-based monomers; (B) copolymers formed from the copolymerization of methyl acrylate or methyl methacrylate with at least one monomer selected from styrene, ethyl methacrylate, and methyl acrylate; and (C) polymers formed from the polymerization of dimethyl acrylate-based monomers.

13. The bone cement composition of claim 1, wherein the acrylic monomer is selected from the group consisting of methyl methacrylate (MMA), ethyl methacrylate (EMA), butyl methacrylate, methyl acrylate (MA), bisphenol A-diglycidyl dimethacrylate (Bis-GMA), 2,2-bis[4-(3-methyl propenoxy-2-hydroquinone propoxyl)phenyl]propane, 2,2-bis(4-methylpropenoxyethoxyphenyl)propane (Bis-MEPP), triethylene glycol dimethacrylate (TEGDMA), diethylene glycol dimethacrylate (DEGDMA), ethylene glycol dimethacrylate (EGDMA), and a combination thereof.

14. A bone cement composition kit comprising a bone matrix component, a powder component, and a liquid component, respectively stored in separate containers, wherein the bone matrix component comprises a bone matrix, the powder component comprises an acrylic polymer, and the liquid component comprises an acrylic monomer, wherein the powder component and the liquid component forms a bone cement matrix component, and the ratio of the bone matrix component to the bone cement matrix component is in a range from about 1:2 (ml/ml) to about 1:50 (ml/ml), wherein the bone cement composition kit further comprises a polymerization initiator and a polymerization promoter with the proviso that the polymerization initiator and the polymerization promoter are not provided in the same component at the same time.

15. The bone cement composition kit of claim 14, wherein the bone matrix component further comprises a vehicle, wherein the vehicle is selected from the group consisting of cellulose, cellulose derivatives, glycerol, polyethylene glycol (PEG), glycosaminoglycan, collagen, gelatin, ethylene glycol, propylene glycol, polyhydroxyalkanoate (PHA), polylactic acid (PLA), polyglycolic acid (PGA),poly(lactic-co-glycolic acid) (PLGA), polycaprolactone (PCL), and a mixture thereof.

16. The bone cement composition kit of claim 15, wherein the cellulose derivatives is selected from the group consisting of methyl cellulose, sodium carboxymethyl cellulose, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), ethyl cellulose, hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC), and a mixture thereof; the polyethylene glycol is selected from the group consisting of polyethylene glycol 600 (PEG600), polyethylene glycol 4000 (PEG4000) and a mixture thereof; and the glycosaminoglycan is selected from the group consisting of hyaluronan, chondroitin sulfate and derivatives thereof, and a mixture thereof.

17. The bone cement composition kit of claim 14, wherein the bone matrix component is provided in the bone cement composition kit in the form of clay, granule, or powder.

18. The bone cement composition kit of claim 14, wherein the ratio of the powder component to the liquid component is in a range from about 0.5:1 (g/g) to about 3:1 (g/g).

19. The bone cement composition kit of claim 14, wherein the polymerization initiator is selected from the group consisting of benzoyl peroxide, tert-butyl hydroperoxide, lauroyl peroxide, azobisisobutyronitrile, and a mixture thereof.

20. The bone cement composition kit of claim 14, wherein the polymerization promoter is selected from the group consisting of N,N-dimethyl-p-toluidine, 2,4,6-tris(dimethylaminomethyl)phenol, and a mixture thereof.

21. The bone cement composition kit of claim 14, further comprising a polymerization inhibitor, wherein the polymerization inhibitor is provided in the liquid component.

22. The bone cement composition kit of claim 14, wherein the bone matrix has a main constituent selected from phosphates, sulfates, bioglass (Na.sub.2OCaOSiO.sub.2P.sub.2O.sub.5), and a mixture thereof.

23. The bone cement composition kit of claim 22, wherein the main constituent is a phosphate selected from the group consisting of hydroxyapatite (HA), -tricalcium phosphate (-TCP), tetracalcium phosphate, calcium hydrogen phosphate (CaHPO.sub.4), octacalcium phosphate (Ca.sub.8H.sub.2(PO.sub.4).sub.6.Math.5 H.sub.2O), calcium pyrophosphate (Ca.sub.2P.sub.2O.sub.7), amorphous calcium phosphate (ACP), magnesium dihydrogen phosphate, magnesium hydrogen phosphate, magnesium phosphate, magnesium ammonium phosphate, magnesium ammonium phosphate hexahydrate, strontium phosphate, strontium hydrogen phosphate, strontium dihydrogen phosphate, and a mixture thereof.

24. The bone cement composition kit of claim 22, wherein the main constituent is a sulfate selected from the group consisting of calcium sulfate dihydrate, calcium sulfate hemihydrate, calcium sulfate anhydrate, magnesium sulfate, magnesium sulfate monohydrate, magnesium sulfate heptahydrate, strontium sulfate, and a mixture thereof.

25. The bone cement composition kit of claim 14, wherein the acrylic polymer is selected from the group consisting of (A) poly(alkyl acrylates) formed from the polymerization of alkyl acrylate-based monomers; (B) copolymers formed from the copolymerization of methyl acrylate or methyl methacrylate with at least one monomer selected from styrene, ethyl methacrylate, and methyl acrylate; and (C) polymers formed from the polymerization of dimethyl acrylate-based monomers.

26. The bone cement composition kit of claim 14, wherein the acrylic monomer is selected from the group consisting of methyl methacrylate (MMA), ethyl methacrylate (EMA), butyl methacrylate, methyl acrylate (MA), bisphenol A-diglycidyl dimethacrylate (Bis-GMA), 2,2-bis[4-(3-methyl propenoxy-2-hydroquinone propoxyl)phenyl]propane, 2,2-bis(4-methylpropenoxyethoxyphenyl)propane (Bis-MEPP), triethylene glycol dimethacrylate (TEGDMA), diethylene glycol dimethacrylate (DEGDMA), ethylene glycol dimethacrylate (EGDMA), and a combination thereof.

27. A method of treating a bone defect comprising administrating to a bone region with a defect the bone cement composition of claim 1.

28. A method of treating a bone defect comprising administrating to a bone region with a defect the bone cement composition kit of claim 14.

Description

DETAILED DESCRIPTION

[0041] Specific examples of the present disclosure are provided below; however, the present disclosure is not limited to these specific examples.

[0042] In the following specific examples, the amount of each component is expressed as the weight percent (wt %).

Example I

Preparation of Bone Cement Composition 1

[0043] 26.4% glycerol, 23.2% PEG600, 17.8% PEG 4000, 6.9% CMC, and 25.7% tricalcium phosphate (TCP) were mixed to form a clay component.

[0044] Further, 64.96% poly(methyl methacrylate) (PMMA), 35% BaSO.sub.4 and 0.04% benzoyl peroxide (BPO) were mixed to form a powder component. In this example, the viscosity of the PMMA was 145 ml/g with a central particle size of 55 m and having 0.4% BPO.

[0045] Additionally, 98.8% methyl methacrylate (MMA), 1.2% N,N-dimethyl-p-toluidine(N,N-dimethyl-p-toluidine, DMPT) and 20 ppm hydroquinone (HQ) were mixed to form a liquid component.

[0046] Last, in a dual-cylinder injector with a volume ratio of 10:1, the clay component was filled into the cylinder with the smaller volume. Also, in a centrifuge tube, the powder component and the liquid component were mixed in a ratio of 2 g/mL at a temperature of 23 C.1 C., and these two components were mixed by shaking. Start timing when the powder component and the liquid component came into contact, and approximately one minute later, the mixture was filled into the other cylinder with the greater volume. Approximately 3 minutes later, a combining nozzle was installed on the dual-cylinder syringe, and the injection started. The bone cement composition injected from the dual-cylinder syringe was also referred to as the bone cement composition 1.

[0047] The time point at which the injected bone cement composition 1 was in an un-runny state was recorded, and this time point was designated as the starting point of the injection operation. The injectability of the bone cement composition 1 was recorded every 30 seconds, and the time point at which the composition was no longer injectable was recorded and used as the stop point of the injection operation. Meanwhile, the injected bone cement composition 1 was filled into a mold and made into five cylinders having the size of 12 mm (length)6 mm (diameter); the molded cylinders were stood for 24 hours and then subjected to ISO-5833 test to determine the compressive strength thereof.

[0048] The injection period for the bone cement composition 1 was 5 minutes to 12 minutes; the compressive strength thereof was 60.93.3 MPa.

Example II

Preparation of Bone Cement Composition 2

[0049] 24.8% glycerol, 21.8% PEG600, 16.8% PEG 4000, 6.4% CMC, 24.2% TCP, and 6.0% BPO were mixed to form a clay component.

[0050] Further, 65% PMMA and 35% barium sulfate were mixed to form a powder component. The viscosity of the PMMA was 145 ml/g with a central particle size of 55 m and having 0.4% BPO.

[0051] Additionally, 98.8% MMA, 1.2% DMPT and 20 ppm HQ were mixed to form a liquid component.

[0052] Last, in a dual-cylinder injector with a volume ratio of 10:1, the clay component was filled into the cylinder with the smaller volume. In addition, in a centrifuge tube, the powder component and the liquid component were mixed in a ratio of 2 g/mL at a temperature of 23 C.1 C., and these two components were mixed by shaking. Start timing when the powder component and the liquid component came into contact, and approximately one minute later, the mixture was filled into the other cylinder with the greater volume. Approximately 3 minutes later, a combining nozzle was installed on the dual-cylinder syringe, and the injection started. The bone cement composition injected from the dual-cylinder syringe was also referred to as the bone cement composition 2.

[0053] The time point at which the injected bone cement composition 2 was in an un-runny state was recorded, and this time point was designated as the starting point of the injection operation. The injectability of the bone cement composition 2 was recorded every 30 seconds, and the time point at which the composition was no longer injectable was recorded and used as the stop point of the injection operation. Meanwhile, the injected bone cement composition 2 was filled into a mold and made into five cylinders having the size of 12 mm (length)6 mm (diameter); the molded cylinders were stood for 24 hours and then subjected to ISO-5833 test to determine the compressive strength thereof.

[0054] The injection period for the bone cement composition 2 was 5.5 minutes to 14 minutes; the compressive strength thereof was 72.21.0 MPa.

Example III

Preparation of Bone Cement Composition 3

[0055] 25.5% glycerol, 22.4% PEG600, 17.2% PEG 4000, 6.6% CMC, 24.8% TCP, and 3.6% DMPT were mixed to form a clay component.

[0056] Further, 64.5% PMMA, 35% barium sulfate and 0.5% BPO were mixed to form a powder component. The viscosity of the PMMA was 145 ml/g with a central particle size of 55 m and having 0.4% BPO.

[0057] Additionally, 100% MMA and 30 ppm MEHQ were mixed to form a liquid component.

[0058] Last, in a dual-cylinder injector with a volume ratio of 10:1, the clay component was filled into the cylinder with the smaller volume, whereas the powder component was filled into the other cylinder with the greater volume. Also, the powder component and the liquid component were mixed in a ratio of 2 g/mL by adding the liquid component into the powder component at a temperature of 23 C.1 C., and these two components were mixed by shaking the dual-cylinder syringe for about 1 minute. Start timing when the powder component and the liquid component came into contact. Approximately 3 minutes later, a combining nozzle was installed on the dual-cylinder syringe, and the injection started. The bone cement composition injected from the dual-cylinder syringe was also referred to as the bone cement composition 3.

[0059] The time point at which the injected bone cement composition 3 was in an un-runny state was recorded, and this time point was designated as the starting point of the injection operation. The injectability of the bone cement composition 3 was recorded every 30 seconds, and the time point at which the composition was no longer injectable was recorded and used as the stop point of the injection operation. Meanwhile, the injected bone cement composition 3 was filled into a mold and made into five cylinders having the size of 12 mm (length)6 mm (diameter); the molded cylinders were stood for 24 hours and then subjected to ISO-5833 test to determine the compressive strength thereof.

[0060] The injection period for the bone cement composition 3 was 5 minutes to 13 minutes; the compressive strength thereof was 76.36.4 MPa.

[0061] In the bone cement composition 3, since the liquid component did not contain DMPT, the powder component and the liquid component did not harden upon being mixed, and only the injected bone cement composition 3 hardened. After the powder component and the liquid component were mixed, the viscosity increased continuously because of the dissolution of PMMA, and reached a stable level about 30 minutes later; however, about 13 minutes after mixing, the viscosity became too high so that the bone cement composition 3 was no longer injectable.

Example IV

Preparation of Bone Cement Composition 4

[0062] 13.2% glycerol, 18.0% PEG600, 18.0% PEG 4000, 10.8% CMC, 30.0% TCP, and 10.0% DMPT were mixed to form a clay component.

[0063] Further, 31.5% PMMA1, 6.0% PMMA2, 55% barium sulfate and 7.5% TCP were mixed to form a powder component. The viscosity of PMMA1 was 90 ml/g with a central particle size of 40 m and having 5% BPO; the viscosity of PMMA2 was 300 ml/g with a central particle size of 40 m and having 0.3% BPO.

[0064] Additionally, 100% MMA and 30 ppm MEHQ were mixed to form a liquid component.

[0065] Last, in a dual-cylinder injector with a volume ratio of 10:1, the clay component was filled into the cylinder with the smaller volume, whereas the powder component was filled into the other cylinder with the greater volume. Also, the powder component and the liquid component were mixed in a ratio of 1.5 g/mL by adding the liquid component into the powder component at a temperature of 23 C.1 C., and these two components were mixed by shaking the dual-cylinder syringe for about 1 minute. Start timing when the powder component and the liquid component came into contact. Approximately 8 minutes later, a combining nozzle was installed on the dual-cylinder syringe, and the injection started. The bone cement composition injected from the dual-cylinder syringe was also referred to as the bone cement composition 4.

[0066] The time point at which the injected bone cement composition 4 was in an un-runny state was recorded, and this time point was designated as the starting point of the injection operation. The injectability of the bone cement composition 4 was recorded every 30 seconds, and the time point at which the composition was no longer injectable was recorded and used as the stop point of the injection operation. Meanwhile, the injected bone cement composition 4 was filled into a mold and made into five cylinders having the size of 12 mm (length)6 mm (diameter); the molded cylinders were stood for 24 hours and then subjected to ISO-5833 test to determine the compressive strength thereof.

[0067] The injection period for the bone cement composition 4 was 9 minutes to more than one hour; the compressive strength thereof was 68.11.1 MPa.

[0068] In the bone cement composition 4, since the liquid component did not contain DMPT, the powder component and the liquid component did not harden upon being mixed, and only the injected bone cement composition 4 hardened. After the powder component and the liquid component were mixed, the viscosity increased continuously because of the dissolution of PMMA, and by using PMMA with a smaller size, the viscosity reached a stable level about 10 minutes later, and was injectable thereafter.

Example V

Preparation of Bone Cement Composition 5

[0069] 22.0% glycerol, 20.0% PEG600, 16.0% PEG 4000, 7.0% CMC, 30.0% TCP, and 5.0% DMPT were mixed to form a clay component.

[0070] Further, 34.5% PMMA, 58% barium sulfate and 7.5% TCP were mixed to form a powder component. The viscosity of the PMMA was 90 ml/g with a central particle size of 40 m and having 5% BPO.

[0071] Additionally, 100% MMA and 30 ppm MEHQ were mixed to form a liquid component.

[0072] Last, in a dual-cylinder injector with a volume ratio of 10:1, the clay component was filled into the cylinder with the smaller volume, whereas the powder component was filled into the other cylinder with the greater volume. Also, the powder component and the liquid component were mixed in a ratio of 1.5 g/mL by adding the liquid component into the powder component at a temperature of 23 C.1 C., and these two components were mixed by shaking the dual-cylinder syringe for about 1 minute. Start timing when the powder component and the liquid component came into contact. Approximately 8 minutes later, a combining nozzle was installed on the dual-cylinder syringe, and the injection started. The bone cement composition injected from the dual-cylinder syringe was also referred to as the bone cement composition 4.

[0073] The time point at which the injected bone cement composition 5 was in an un-runny state was recorded, and this time point was designated as the starting point of the injection operation. The injectability of the bone cement composition 5 was recorded every 30 seconds, and the time point at which the composition was no longer injectable was recorded and used as the stop point of the injection operation. Meanwhile, the injected bone cement composition 5 was filled into a mold and made into five cylinders having the size of 12 mm (length)6 mm (diameter); the molded cylinders were stood for 24 hours and then subjected to ISO-5833 test to determine the compressive strength thereof.

[0074] The injection period for the bone cement composition 5 was 12 minutes to more than one hour; the compressive strength thereof was 70.52.7 MPa.

[0075] In the bone cement composition 5, since the liquid component did not contain DMPT, the powder component and the liquid component did not harden upon being mixed, and only the injected bone cement composition 5 hardened. After the powder component and the liquid component were mixed, the viscosity increased continuously because of the dissolution of PMMA, and by using PMMA with a smaller size, the viscosity reached a stable level about 12 minutes later, and was injectable thereafter.

Example VI

Preparation of Bone Cement Composition 6

[0076] 13.2% glycerol, 18.0% PEG600, 18.0% PEG 4000, 10.8% CMC, 30.0% TCP, and 5.0% DMPT were mixed to form a clay component.

[0077] Further, 31.5% PMMA1, 6.0% PMMA2, 55% barium sulfate and 7.5% TCP were mixed to form a powder component. The viscosity of PMMA1 was 90 ml/g with a central particle size of 40 m and having 5% BPO; the viscosity of PMMA2 was 300 ml/g with a central particle size of 40 m and having 0.3% BPO.

[0078] Additionally, 90% MMA, 10% poly (ethylene glycol) diacrylate, and 30 ppm MEHQ were mixed to form a liquid component.

[0079] Last, in a dual-cylinder injector with a volume ratio of 10:1, the clay component was filled into the cylinder with the smaller volume. Also, in a centrifuge tube, the powder component and the liquid component were mixed in a ratio of 1.5 g/mL at a temperature of 23 C.1 C., and these two components were mixed by shaking. Start timing when the powder component and the liquid component came into contact, and approximately one minute later, the mixture was filled into the other cylinder with the greater volume. Approximately 8 minutes later, a combining nozzle was installed on the dual-cylinder syringe, and the injection started. The bone cement composition injected from the dual-cylinder syringe was also referred to as the bone cement composition 6.

[0080] The time point at which the injected bone cement composition 6 was in an un-runny state was recorded, and this time point was designated as the starting point of the injection operation. The injectability of the bone cement composition 6 was recorded every 30 seconds, and the time point at which the composition was no longer injectable was recorded and used as the stop point of the injection operation. Meanwhile, the injected bone cement composition 6 was filled into a mold and made into five cylinders having the size of 12 mm (length)6 mm (diameter); the molded cylinders were stood for 24 hours and then subjected to ISO-5833 test to determine the compressive strength thereof.

[0081] The injection period for the bone cement composition 6 was 12 minutes to more than one hour; the compressive strength thereof was 72.82.7 MPa.

[0082] In the bone cement composition 6, since the liquid component did not contain DMPT, the powder component and the liquid component did not harden upon being mixed, and only the injected bone cement composition 6 hardened. After the powder component and the liquid component were mixed, the viscosity increased continuously because of the dissolution of PMMA, and by using PMMA with a smaller size, the viscosity reached a stable level about 12 minutes later, and was injectable thereafter.

Example VII

Preparation of Bone Cement Composition 7

[0083] 13.2% glycerol, 18.0% PEG600, 18.0% PEG 4000, 10.8% CMC, 30.0% TCP, and 5.0% DMPT were mixed to form a clay component.

[0084] Further, 31.5% PMMA1, 6.0% PMMA2, 55% barium sulfate and 7.5% TCP were mixed to form a powder component. The viscosity of PMMA1 was 90 ml/g with a central particle size of 40 m and having 5% BPO, the viscosity of PMMA2 was 300 ml/g with a central particle size of 40 m and having 0.3% BPO.

[0085] Additionally, 100% MMA and 30 ppm MEHQ were mixed to form a liquid component.

[0086] Last, in a dual-cylinder injector with a volume ratio of 4:1, the clay component was filled into the cylinder with the smaller volume, whereas the powder component was filled into the other cylinder with the greater volume. Also, the powder component and the liquid component were mixed in a ratio of 1.5 g/mL by adding the liquid component into the powder component at a temperature of 23 C.1 C., and these two components were mixed by shaking the dual-cylinder syringe for about 1 minute. Start timing when the powder component and the liquid component came into contact. Approximately 8 minutes later, a combining nozzle was installed on the dual-cylinder syringe, and the injection started. The bone cement composition injected from the dual-cylinder syringe was also referred to as the bone cement composition 7.

[0087] The time point at which the injected bone cement composition 7 was in an un-runny state was recorded, and this time point was designated as the starting point of the injection operation. The injectability of the bone cement composition 7 was recorded every 30 seconds, and the time point at which the composition was no longer injectable was recorded and used as the stop point of the injection operation. Meanwhile, the injected bone cement composition 7 was filled into a mold and made into five cylinders having the size of 12 mm (length)6 mm (diameter); the molded cylinders were stood for 24 hours and then subjected to ISO-5833 test to determine the compressive strength thereof.

[0088] The injection period for the bone cement composition 7 was 12 minutes to more than one hour; the compressive strength thereof was 44.60.6 MPa.

[0089] In the bone cement composition 7, since the liquid component did not contain DMPT, the powder component and the liquid component did not harden upon being mixed, and only the injected bone cement composition 7 hardened. After the powder component and the liquid component were mixed, the viscosity increased continuously because of the dissolution of PMMA, and by using PMMA with a smaller size, the viscosity reached a stable level about 12 minutes later, and was injectable thereafter. In the bone cement composition 7, the mechanical property decreased as the ratio of the clay component was increased; hence, depending on the settings of the clinical applications bone cement composition with decreased mechanical property may exhibit a better clinical performance.